China Aerospace Science and Technology Corporation’s (CASC) latest and most capable attack and reconnaissance unmanned aerial vehicle (UAV), the Caihong 5 (CH-5), or Rainbow 5, will be fitted with a new heavy fuel engine, which will increase the endurance and range of the aircraft.

According to the chief designer of the CH series, Shi Wen, quoted in Chinese state media (and first reported by dafeng cao), the heavy fuel engine will extend the CH-5’s endurance to 60 hours and its range to over 10,000 kilometers. This constitutes approximately a 20 to 30 percent increase, Shi is quoted as saying.

There have been repeated reports that the CH-5 has already been fitted with a heavy fuel engine in the past and publicly available information has regularly cited the UAV’s endurance at around 60 hours and its range at 6,500 to 10,000 kilometers. As I explained in July 2017:

(…) Reports indicate that the maximum range of the UAV is 6,500 kilometers and will eventually be increased to 10,000 kilometers (…) Powered by a 330 hp heavy fuel engine (HFE), the drone has an operating endurance of up to 60 hours and a purported service ceiling of 30,000 ft (7,000 m).

The majority of sources, however, cite a 48-hour endurance and maximum range of around 8,000 kilometers. Given China’s still limited command and control capabilities, the CH-5’s actual operational range is likely around 250 kilometers via line-of-sight datalink and approximately 2,000 kilometers with satellite communication.

According to Shi, the new heavy fuel engine is slated to be installed and tested in the coming months. Most Western-made UAVs are powered by heavy fuel engines. Heavy fuel is denser and contains more energy than regular gasoline, which translates into greater endurance and range for aircraft limited in their fuel volume.

In 2016, I described the technical characteristics of China’s latest UAV:

The medium-altitude long-endurance (MALE) CH-5 purportedly has a wingspan of 21 meters and can carry a payload of up to 1,200 kilograms (previous reports indicated 900 kilograms) – 2.6 times more than previous combat UAVs of the CH series. Overall, the CH-5 can carry up to 16 air-to-ground weapons including Lan Jian 7 (Blue Arrow 7) laser-guided air-to-surface missiles, TG100 laser/INS/GPS-guided bombs, and AR-1/HJ-10 anti-tank missiles.

However, the CH-5 is thought to have more limited endurance, range, speed, and detection capabilities than U.S. models such as the General Atomics MQ-9 Reaper.

The CH-5’s maiden flight was conducted at an undisclosed airfield in Gansu province, China in August 2015. The flight lasted for about 20 minutes. A prototype of the new UAV was publicly displayed for the first time in November 2016. Last summer, CASC announced that the drone is ready for mass production. Like previous models of the Rainbow UAV series, the CH-5 is designed for export.